Extended statistics on expressions
Allow defining extended statistics on expressions, not just just on
simple column references. With this commit, expressions are supported
by all existing extended statistics kinds, improving the same types of
estimates. A simple example may look like this:
CR
Reduce duration of stats_ext regression tests
The regression tests of extended statistics were taking a fair amount of
time, due to using fairly large data sets with a couple thousand rows.
So far this was fine, but with tests for statistics on expressions the
duration would get a bit excessive.
Fix ndistinct estimates with system attributes
When estimating the number of groups using extended statistics, the code
was discarding information about system attributes. This led to strange
situation that
SELECT 1 FROM t GROUP BY ctid;
could have produced higher estimate (equal to pg_class
Fix ndistinct estimates with system attributes
When estimating the number of groups using extended statistics, the code
was discarding information about system attributes. This led to strange
situation that
SELECT 1 FROM t GROUP BY ctid;
could have produced higher estimate (equal to pg_class
Fix ndistinct estimates with system attributes
When estimating the number of groups using extended statistics, the code
was discarding information about system attributes. This led to strange
situation that
SELECT 1 FROM t GROUP BY ctid;
could have produced higher estimate (equal to pg_class
Fix ndistinct estimates with system attributes
When estimating the number of groups using extended statistics, the code
was discarding information about system attributes. This led to strange
situation that
SELECT 1 FROM t GROUP BY ctid;
could have produced higher estimate (equal to pg_class
Fix ndistinct estimates with system attributes
When estimating the number of groups using extended statistics, the code
was discarding information about system attributes. This led to strange
situation that
SELECT 1 FROM t GROUP BY ctid;
could have produced higher estimate (equal to pg_class
Merge similar algorithms into roles_is_member_of().
The next commit would have complicated two or three algorithms, so take
this opportunity to consolidate. No functional changes.
Reviewed by John Naylor.
Discussion: https://postgr.es/m/20201228043148.ga1053...@rfd.leadboat.com
Branch
--
m
Add "pg_database_owner" default role.
Membership consists, implicitly, of the current database owner. Expect
use in template databases. Once pg_database_owner has rights within a
template, each owner of a database instantiated from that template will
exercise those rights.
Reviewed by John Nayl
Fix alignment in BRIN minmax-multi deserialization
The deserialization failed to ensure correct alignment, as it assumed it
can simply point into the serialized value. The serialization however
ignores alignment and copies just the significant bytes in order to make
the result as small as possible
BRIN minmax-multi indexes
Adds BRIN opclasses similar to the existing minmax, except that instead
of summarizing the page range into a single [min,max] range, the summary
consists of multiple ranges and/or points, allowing gaps. This allows
more efficient handling of data with poor correlation to
BRIN bloom indexes
Adds a BRIN opclass using a Bloom filter to summarize the range. Indexes
using the new opclasses allow only equality queries (similar to hash
indexes), but that works fine for data like UUID, MAC addresses etc. for
which range queries are not very common. This also means the ind
Support the old signature of BRIN consistent function
Commit a1c649d889 changed the signature of the BRIN consistent function
by adding a new required parameter. Treating the parameter as optional,
which would make the change backwards incompatibile, was rejected with
the justification that there
Remove unnecessary pg_amproc BRIN minmax entries
The BRIN minmax opclasses included amproc entries with mismatching left
and right types, but those happen to be unnecessary. The opclasses only
need cross-type operators, not cross-type support procedures. Discovered
when trying to define equivalen
From: Robert Haas
> On Wed, Mar 24, 2021 at 12:48 AM Andres Freund
> wrote:
> > Although this specific hack doesn't seem too terrible to me. If you
> > execute a parallel insert the likelihood to end up not needing an xid is
> > pretty low. Implementing it concurrently does seem like it'd end up
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